What did life look like when the Amazon watershed flowed backwards? How did its direction shape the evolution of life around it? And what force could have possibly been strong enough to up-end one of the world’s mightiest rivers between then and now?

It was long assumed that Amazons, the fierce and fearsome women warriors of Greece, were imaginary. But curiously enough, stories from ancient Egypt, Persia, the Middle East, Central Asia, India and China also featured Amazon-like warrior women. And Amazo...

The Amazon has always been one of the most mysterious places on earth.